1. Field of the Invention
An aspect of the present invention relates to an apparatus for clamping a hard disk on a motor.
2. Description of the Related Art
In a conventional hard disk drive, as shown in FIG. 1, a hard disk D where predetermined information is recorded is fixed on a motor rotating body 4 by a predetermined clamping apparatus to be capable of rotating. An actuator 2 on which a magnetic head 2a is mounted and rotating around a rotation shaft 2b provided on a base 1 is provided at one side of the hard disk D. When information is recorded and reproduced with respect to the hard disk D, the motor rotating body 4 rotates, which causes the hard disk D to rotate. The actuator 2 moves the magnetic head 2a to a desired position on a track of the hard disk D so that the recording and reproduction processes can be performed.
In FIGS. 1 and 2, the clamping apparatus for fixing the hard disk D on the motor rotating body 4, comprises a spacer 5 inserted around a boss 4a of the motor rotating body 4 disposed on an upper surface of the hard disk D, a damper 3 accommodated on the spacer 5, and a plurality of screws 6 for coupling the damper 3 to the motor rotating body 4. Thus, when the plurality of screws 6 are coupled to coupling holes 4c of the motor rotating body 4 through through holes 3a of the damper 3, an edge portion of the damper 3 presses the spacer 5 by a screwing force. Then, the spacer 5 presses the hard disk D toward an accommodation surface 4b of the motor rotating body 4 so that the hard disk D is fixed on the motor rotating body 4. The above clamping structure using a plurality of screws 6 is disclosed in Japanese Patent Publication No. hei 9-91816, Japanese Patent Publication No. hei 10-162464, and Japanese Patent Publication No. 2000-195212.
However, when the plurality of screws 6 are screwed too tightly, a displacement is generated to the hard disk D receiving the screwing force so that deviation in the height at which the magnetic head 2a is lifted may be severe.
A servo signal such as information about the position where information is to be stored is recorded on the hard disk D. In some cases, a servo signal is recorded after the hard disk D is assembled. However, in other cases, a servo signal is first recorded on the hard disk D and then the hard disk D is assembled. Accordingly, when a displacement is generated to the hard disk D during assembly, the servo signal already recorded on the hard disk D may be damaged. Also, abrasion dust can be generated from the plurality of screws 6, an inner wall of the through hole 3a of the damper 3, or an inner wall of the coupling hole 4c of the motor rotating body 4, which may damage the surface of the hard disk D. Furthermore, since four screws 6 need to be screwed several times one by one in order to apply an identical pressing force to each screw, working time is prolonged.
Therefore, a new clamping structure which can overcome these problems is needed.